What size is an AS568-001 o-ring?

An AS568-001 o-ring has an inside diameter of 0.0290 in (0.740 mm) and a cross-section of 0.0400 in (1.020 mm), giving an outside diameter of 0.1090 in (2.780 mm).

What is an AS568-001 o-ring in mm?

0.740 mm inside diameter × 1.020 mm cross-section, 2.780 mm outside diameter. AS568 is an inch standard, so these are exact conversions rather than metric nominal sizes.

What is the tolerance on an AS568-001 o-ring?

AS568 allows ± 0.0039 in (± 0.100 mm) on the inside diameter and ± 0.0031 in (± 0.080 mm) on the cross-section, measured free-state.

Which AS568 series is the AS568-001 o-ring in?

Dash 001 is in the 001-003 band — AS568 dash 001-003, a 0.040-0.060 in cross-section. Every size in that band shares the same cross-section and therefore the same gland depth.

AS568 · dash 001 · 0.040-0.060 in cross-section

AS568-001 O-Ring Size — ID, Cross-Section, OD and Gland Data

https://shopmath.org/o-rings/as568-001 · data verified August 1, 2026

An AS568-001 o-ring is 0.0290 in (0.740 mm) inside diameter with a 0.0400 in (1.020 mm) cross-section, giving a 0.1090 in (2.780 mm) outside diameter. Dimensions are free-state, before installation.

Dash: 001
ID: 0.0290 in
CS: 0.0400 in
OD: 0.1090 in
Series: 001-003

AS568-001 o-ring · inside Ø × cross-section

0.0290 × 0.0400 in

Inside Ø: 0.740mm
Cross-section: 1.020mm
Outside Ø: 2.780mm

Free-state dimensions with AS568 tolerances of ± 0.0039 in on the ID and ± 0.0031 in on the cross-section.

AS568-001 O-Ring Dimensions and Tolerances

An AS568 o-ring is specified by its inside diameter and cross-section; the outside diameter follows from them. Tolerances are the AS568 free-state limits, measured uninstalled.

AS568-001 o-ring — inside diameter, cross-section and outside diameter with tolerances
Dimension	Inch	Millimetre
Inside diameter (ID)	0.0290 ± 0.0039	0.740 ± 0.100
Cross-section (CS / W)	0.0400 ± 0.0031	1.020 ± 0.080
Outside diameter (OD)	0.1090	2.780

OD = ID + 2 × CS. Elastomer parts are measured free-state and relax over time; the tolerances above are manufacturing limits, not the installed dimensions.

AS568-001 O-Ring Size in Millimetres

AS568 is an inch standard. These are the same dimensions converted exactly (1 in = 25.4 mm) — an AS568 size is not interchangeable with an ISO 3601 metric size that happens to be close.

AS568-001 o-ring — metric dimensions
Dimension	Inch	Millimetre
Nominal ID × CS	0.0290 × 0.0400 in	0.740 × 1.020 mm
Nominal OD × CS	0.1090 × 0.0400 in	2.780 × 1.020 mm

Metric figures are conversions of the AS568 inch dimensions, rounded to 0.01 mm as the source data carries them. A metric o-ring called out as 25 × 3.5 mm is a different part.

AS568 O-Ring Sizes Closest to AS568-001

Ordered by how close the inside diameter is, across every cross-section series. A near-ID match in a different cross-section will not seal the same gland.

AS568 o-ring sizes with an inside diameter closest to AS568-001
Property	Inside Ø		Property	Property	Property
Size	in	mm	Cross-section, in	Outside Ø, in	ID difference, mm
AS568-002	0.0420	1.070	0.0500	0.1420	+0.330
AS568-102	0.0490	1.240	0.1030	0.2550	+0.500
AS568-003	0.0560	1.420	0.0600	0.1760	+0.680
AS568-004	0.0700	1.780	0.0700	0.2100	+1.040
AS568-103	0.0810	2.060	0.1030	0.2870	+1.320
AS568-005	0.1010	2.570	0.0700	0.2410	+1.830

Check the cross-section before substituting: the gland depth is set by cross-section, not by inside diameter.

Sources and Method for the AS568-001 O-Ring Size

Size and tolerancescomputed+compiled

bd_warehouse o-ring_parameters.csv (Apache-2.0) and bckasper3/KasperCalc oring-sizes.js (MIT), agreeing on all 349 sizes; OD computed as ID + 2 x CS

Verified against two independent open datasets agreeing on all 349 sizes; fabricated-dataset negative control passed; 21 checks total

Part computed from the standard's formulas, part compiled from agreeing public sources.

Formula

Outside diameter

OD  =  ID + 2 × CS

  0.0290 + 2 × 0.0400  =  0.1090 in

Assumptions

Dimensions are free-state, at room temperature, before installation.
Tolerances are AS568 manufacturing limits. Compression set, swell in service fluid and thermal expansion all move the installed dimensions and are properties of the compound, not of the size.
Dataset scope: A fabricated-dataset negative control is asserted against on every run. EXCLUDED: groove width, corner radius, diametral clearance, back-up ring widths, surface finish, all dynamic glands, the 900-series, and ISO 3601 metric sizes.

Data last verified

August 1, 2026

How this data is built and checked →

How to Cite This AS568-001 O-Ring Reference

Citation

ShopMath. "AS568-001 O-Ring Size — ID, Cross-Section, OD and Gland Data." ShopMath, verified August 1, 2026, https://shopmath.org/o-rings/as568-001

BibTeX

@misc{shopmath-o-rings-as568-001,
  title        = {AS568-001 O-Ring Size — ID, Cross-Section, OD and Gland Data},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/o-rings/as568-001}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/o-rings/as568-001

Common Questions About the AS568-001 O-Ring

What size is an AS568-001 o-ring?: An AS568-001 o-ring has an inside diameter of 0.0290 in (0.740 mm) and a cross-section of 0.0400 in (1.020 mm), giving an outside diameter of 0.1090 in (2.780 mm).
What is an AS568-001 o-ring in mm?: 0.740 mm inside diameter × 1.020 mm cross-section, 2.780 mm outside diameter. AS568 is an inch standard, so these are exact conversions rather than metric nominal sizes.
What is the tolerance on an AS568-001 o-ring?: AS568 allows ± 0.0039 in (± 0.100 mm) on the inside diameter and ± 0.0031 in (± 0.080 mm) on the cross-section, measured free-state.
Which AS568 series is the AS568-001 o-ring in?: Dash 001 is in the 001-003 band — AS568 dash 001-003, a 0.040-0.060 in cross-section. Every size in that band shares the same cross-section and therefore the same gland depth.

Complete AS568 size chart · Every AS568 series